Home | History | Annotate | Line # | Download | only in gen
udiv.S revision 1.2.48.1 
      1 /*-
      2  * Copyright (c) 1991, 1993
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * This code is derived from software contributed to Berkeley by
      6  * Donn Seeley at UUNET Technologies, Inc.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of the University nor the names of its contributors
     17  *    may be used to endorse or promote products derived from this software
     18  *    without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     30  * SUCH DAMAGE.
     31  */
     32 
     33 #include <machine/asm.h>
     34 
     35 	/* .asciz "@(#)udiv.s	8.1 (Berkeley) 6/4/93" */
     36 RCSID("$NetBSD: udiv.S,v 1.2.48.1 2011/02/08 16:18:28 bouyer Exp $")
     37 
     38 /*
     39  * Unsigned division, PCC flavor.
     40  * udiv() takes an ordinary dividend/divisor pair;
     41  * audiv() takes a pointer to a dividend and an ordinary divisor.
     42  */
     43 
     44 #define	DIVIDEND	4(%ap)
     45 #define	DIVISOR		8(%ap)
     46 
     47 ASENTRY(__udiv,0)
     48 	movl	DIVISOR,%r2
     49 	jlss	Leasy		# big divisor: settle by comparison
     50 	movl	DIVIDEND,%r0
     51 	jlss	Lhard		# big dividend: extended division
     52 	divl2	%r2,%r0		# small divisor and dividend: signed division
     53 	ret
     54 Lhard:
     55 	clrl	%r1
     56 	ediv	%r2,%r0,%r0,%r1
     57 	ret
     58 Leasy:
     59 	cmpl	DIVIDEND,%r2
     60 	jgequ	Lone		# if dividend is as big or bigger, return 1
     61 	clrl	%r0		# else return 0
     62 	ret
     63 Lone:
     64 	movl	$1,%r0
     65 	ret
     66 END(__udiv)
     67 
     68 ASENTRY(__audiv,0)
     69 	movl	DIVIDEND,%r3
     70 	movl	DIVISOR,%r2
     71 	jlss	La_easy		# big divisor: settle by comparison
     72 	movl	(%r3),%r0
     73 	jlss	La_hard		# big dividend: extended division
     74 	divl2	%r2,%r0		# small divisor and dividend: signed division
     75 	movl	%r0,(%r3)		# leave the value of the assignment in %r0
     76 	ret
     77 La_hard:
     78 	clrl	%r1
     79 	ediv	%r2,%r0,%r0,%r1
     80 	movl	%r0,(%r3)
     81 	ret
     82 La_easy:
     83 	cmpl	(%r3),%r2
     84 	jgequ	La_one		# if dividend is as big or bigger, return 1
     85 	clrl	%r0		# else return 0
     86 	clrl	(%r3)
     87 	ret
     88 La_one:
     89 	movl	$1,%r0
     90 	movl	%r0,(%r3)
     91 	ret
     92 END(__audiv)
     93